Generally, if electronic products such as computers, displays, and mobile terminals do not adequately diffuse heat generated from the inside of the electronic products to the outside thereof, a collision with the residual images on a screen, the failure of the system, etc., may be caused due to excessive accumulation of the heat generated. In addition, due to the excessive accumulation of the heat, the life of the electronic products may be shortened or the source of the explosion and fire may be also provided in severe cases.
In recent years, electronic products including mobile terminals are continuously evolving, and are promoting high performance and multi-function according to user's needs.
In particular, mobile terminals are required to be compact in size and light in weight to maximize the user's portability and convenience, and integrated components are being mounted in a small space for the high-performance. Accordingly, components used in mobile terminals become increasingly high performance to thus increase heating temperature. The increased heating temperature makes an influence upon adjacent components to thus cause the performance of the mobile terminals to be lowered.
A variety of insulating materials are applied in mobile terminals in order to solve problems due to heat generated from the mobile terminals, but optimum insulation materials that are thin and has excellent heat insulation performance have not been developed yet. Thus, a technology of insulation is variously under research and development.
Korean Patent Application Publication No. 2012-0036574 disclosed a complex sheet structure using heat insulation nonwoven fabric including: a nonwoven sheet layer which performs a heat insulation function; an inorganic coating waterproofing layer which is coated on the nonwoven sheet layer and performs a main waterproofing function and an adhesive function; a glass fiber layer one surface of which is bonded and laminated on the inorganic coating waterproofing layer; a solventless urethane waterproofing agent layer which is coated on the glass fiber layer and performs a waterproofing function; and an acrylic resin-based coating agent layer which is coated on the solventless urethane waterproofing agent layer, to thereby provide advantages of improving the durability of the structure and preventing the deformation and the damage of the structure due to external conditions such as heat and impact. However, since the composite sheet structure is configured to form the inorganic coating waterproofing layer only on one surface of the nonwoven fabric sheet layer of performing the heat insulation function, pores of the nonwoven fabric sheet layer are exposed to the outside to thus cause a problem of reducing the heat insulation capability in the nonwoven fabric sheet layer.
Thus, the present inventors have continuously studied a technology of making an excellent heat insulation function with an ultra-thin structure to thereby form a coating film made of a polymeric material on both sides of a nonwoven fabric to thus have derived and invented structural features of a sheet which ensures thickness uniformity, maximizes heat insulation efficiency, and ultra-thins the structure, and to thus have completed a heat insulation sheet according to the present invention, which is more economical, utilizable, and competitive.